From 21:02:53 - 21:04:27 two St Anthony officers, car-to-car, talk to each other about stopping Castile's car. There are 15-minute periods of silence on either side of this clip.
Officer says shots fired at 21:06:10 and continues for 15 minutes. There is no mention of the stop before the shots fired call. (The two shots fired calls are made by different radios.)
In the Fire/EMS dispatch/medic control call re: Philando Castile shooting at 21:07:32 there is back and forth from several authorities about incident response.